Thomas de Mowbray, 1st Duke of Norfolk

Thomas de Mowbray, 1st Duke of Norfolk (22 March 1366-22 September 1399) was an English peer. As a result of his involvement in the power struggles which led up to the fall of Richard II of England, he was banished and died in exile in Venice.

Biography
Thomas de Mowbray was born in Epworth, Lincolnshire, England in 1366, the second son of John de Mowbray, 4th Baron Mowbray. In 1383, he succeeded his brother John Mowbray, 1st Earl of Nottingham as Baron Mowbray and Baron Segrave, and was created Earl of Nottingham. In 1385, he was created Earl Marshal for life, and he fought against Scotland before fighting against France during the Hundred Years' War. In 1389, he became Warden of the East March toward Scotland, holding that position until his death. In 1387, he was one of the Lords Appellant to King Richard II of England who deposed some of the King's court favorites, but he worked his way back into the King's good graces and took part in the murder of the King's uncle Thomas of Woodstock, 1st Duke of Gloucester. In gratitude, he was made Duke of Norfolk in 1397.

Feud with Bolingbroke
In 1398, Norfolk quarreled with Henry Bolingbroke, 1st Duke of Hereford due to mutual suspicions stemming from their roles in the conspiracy against the Duke of Gloucester. Before a duel between them could take place, King Richard II banished them both, and Mowbray left England on 19 October 1398. While in exile, he became Earl of Norfolk upon the death of his grandmother Margaret, Duchess of Norfolk on 24 March 1399. Mowbray died of the plague at Venice on 22 September 1399, and Bolingbroke returned to England and usurped the crown just eight days later. He then had Parliament annul Mowbray's creation as Duke of Norfolk.